Such a conveyor device is known from DE 35 44 447 C2. The known conveyor device includes a conveyor means provided with an essentially V-shaped bow having a runner attached to each free end thereof; by means of these runners, the conveyor means can be suspended from a suitably adapted rail and roll along said rail. In the area of ascending paths in the track, a drive in the form of a chain is provided below the rail. For coupling with the drive means, a drive catch in the form of a pivotable rocker is arranged on the bow of the conveyor means at a point located opposite the chain. The rocker is provided with a plurality of teeth projecting in the direction of the chain, part of said teeth being implemented for engagement between the chain links and another part of said teeth being implemented such that they provide a planar support on the lower surface of the chain so that, under the influence of the conveying pressure, the rocker will force itself into engagement with the chain. When the rocker is in engagement with the chain, this position of engagement can only be released when the chain moves away from the rocker. Hence, it is not possible to release the conveyor means from the drive at an arbitrary position of the track. The known conveyor device is predominantly intended for manual operation, the chain drive being only used for supporting the conveying movement along ascending paths. For an automated conveyor device, for which it is necessary that the conveyor means can be released from the drive means at least at predetermined points in the track, said known conveyor means cannot be used.
For a more or less automated operation, it was therefore suggested e.g. in German Utility Model 91 06 792 that not the conveyor means but the chain should be provided with drive catches with the aid of which the conveyor means are driven even if said drive catches only strike against the conveyor means thus causing said conveyor means to be displaced along the track. The drive catch has a predetermined flexibility so that it can bend and move past the conveyor means when the resistance which the conveyor means offers to the drive means exceeds a predetermined value. The conveyor means can thus be released from the drive means in a simple manner e.g. by causing it to strike against an obstacle.
A further conveyor device provided with a chain drive for the conveyor means can be inferred from German Utility Model 92 06 550. In the case of this conveyor device, carriages are conveyed with the aid of a drive catch in the form of a flap secured to the chain. When the conveyor means is to be released from the drive means, the flap is pivoted out of engagement with the conveyor means.
It is true that an arrangement in which the drive catch is secured to the drive chain is very useful for conveyor devices with regard to a great variety of different cases of use; it permits e.g. a structural design of the conveyor device in the case of which the conveyor means are capable of accumulating without excessive loads being applied to the drive means when the conveyor means strike against an obstacle, and it permits the driving connection between the conveyor means and the drive means to be released at predetermined points of the track; but said arrangement also has serious disadvantages. The conveying distances between the conveyor means, for example, are predetermined by the distances between the drive catches on the drive chain. In addition, a comparatively large amount of space is required especially at the deflection points and the return leg of the chain drive, since also the drive catches must be deflected and returned. In addition, a specific type of drive chains must always be used so as to permit the drive catches to be pressed on and so as to guarantee the predetermined distance between the drive catches.
In comparison with this prior art, it is the object of the present invention to provide a conveyor device permitting a greater scope for the fulfillment of conveying tasks in a structurally simple way.
This object is achieved by the features of the invention.
On the basis of the structural design according to the present invention, the conveyor means can be released from the drive means independently of one another at predetermined points of the track rapidly and with a small amount of wear being caused, whereas the drive element continues to move as before. Notwithstanding this, the distance between the conveyor means can be varied, said distance being only limited by the width of the conveyor means in the conveying direction. The drive can be effected by any suitable chain or by means of drive elements of some other kind, the space required for the drive element being small and no additional drive means being necessary for components that are arranged on the drive element.
The conveying operation, in the case of which the drive catch engages the drive element, is the standard mode of operation, whereas the condition in which the operating means is released from the drive means will only occur when the locking engagement between the arresting member and the drive catch has been released by the separator device. In this way, a reliable conveying operation is guaranteed.
Due to the oblique surfaces extending transversely to the direction of movement of the drive catch, the drive catch will not be subjected to full load until it has assumed its correct position of engagement with the drive element, whereby the amount of wear will be reduced still further.
The spring-loaded condition of the arresting member and the positive locking engagement are solutions which are used for providing the locking engagement between the arresting member and the drive catch and which are specially preferred from the structural point of view.
Alternative structural embodiments of the drive catch can also be particularly efficient in practice.
One preferred structural embodiment of the conveyor means that is particularly suitable for conveyor means which are made of plastic material includes a structural design which is known e.g. from German-Utility Model 92 10 549.
In one particularly important embodiment, the individual components of the conveyor device can accumulate also outside of the separator device, i.e. the conveyor means, which are located one behind the other, are separated from the drive means when one conveyor means accumulates behind the next, so that excessive loads on the drive motor will be avoided.